Symposium Presentation Abstract: Known for their powerful sting, the giant Neotropical bullet ant Paraponera clavata (Formicidae: Paraponerinae) is a conspicuous member of ecosystems in lowland tropical rainforests throughout Central and South America, ranging from Honduras in the north to Brazil and Bolivia in the south. This distribution range is much larger than is typical for ants of a single species. They are the last remaining species in the genus Paraponera, and the only species to the subfamily Paraponerinae. We aimed at analyzing large and small scale genetic patterns in bullet ants. Firstly, on a larger scale, we investigated the phylogeography of the species using the mitochondrial gene, cytochrome oxidase I (mtCOI). More specifically, we asked whether gene flow occurs between geographically well separated sites, or on the contrary, whether populations are genetically isolated leaving room for speciation events. Methods included DNA extraction, PCR, cycle sequencing, and sequence analysis. A central question of this research topic is where the giant bullet ant has its origin and in which direction it populated its current range. Based on a mtCOI sequences, we generated a phylogenetic tree inferred from 43 individuals, including three ponerine outgroup taxa. This revealed that bullet ants arose in the Brazilian Amazon and then spread outward into Peru, Ecuador, and eventually into the Central American countries of Panama, Costa Rica, Nicaragua and Honduras. On the small scale, we investigated genetic colony structure including number of queens and number of mates per queen in a single population. To address this question, we developed microsatellite primers specific to bullet ants. So far, we were able to develop 18 primers variable for bullet ants of which 8 were variable within a single population. These primers will be used to screen 971 ants of 81 nests belonging to a single Costa Rican population.

Original Project Description: The Neotropical bullet ant Paraponera clavata has its name on account of its painful sting. It is said that being stung by a bullet ant feels like being shot by a bullet. This ant is a conspicuous component of lowland Neotropical rainforests. It has an extremely wide distribution ranging from Honduras in the north to Bolivia and Brazil in the south. We will use DNA sequence data (the mitochondrial gene cytochorme oxidase I, mtCOI) to study the genetic population structure and phylogeography of the bullet ant across its entire range in Central and Southern America. More specifically, we are asking whether gene flow occurs between geographically well separated sites or on the contrary, whether populations are genetically isolated leaving room for speciation events. A central question of this research topic is where the giant bullet ant has its origin and in which direction it populated its current range. We will also assess the time frame in which population of the Americas occurred using divergence estimates and fossil calibration, as well as several outgroup taxa. To pursue these topics, we will include ants from several populations throughout the entire distribution range in our studies and analyze data using standard techniques.

Research methods and techniques: Interns will receive training in DNA extraction, PCR, and sequencing in the Museum’s core genetics facility, the Pritzker Laboratory and the DNA Discovery Center. Moreover, interns will learn sequence data analyses and phylogeographic analyses methods.